Cloning a hormone controlling male traits in blue crabs and its regulation by the eyestalk

The full-length cDNA encoding a candidate insulin-like AG hormone, termed Cas-IAG, was isolated from the blue crab Callinectes sapidus.

• Cas-IAG is predicted to be a precursor protein that includes a signal peptide, B chain, C peptide, and A chain.
• The androgenic gland (AG) is the primary source of Cas-IAG expression in male blue crabs.
• Minor expression of Cas-IAG was also observed in the hepatopancreas of male crabs.
• Eyestalk ablation experiments suggest an endocrine relationship between the eyestalk ganglia and the AG.
• Cas-IAG expression may be negatively influenced by substances in the eyestalk ganglia.

Simplified